Sleep apnea, (apnea from the Greek for ?without breath?) is a potentially life threatening sleep disorder characterized by frequent pauses in breath during sleep. Several treatments exist, including machines that assist with keeping the airway open. These sleep apnea machines consist of a small medical pump and a tube connected to a mask, which is worn over the mouth, over the nose, or both. The sleep apnea machines pump a controlled amount of pressurized air into the airway, holding open the relaxed muscles, much like air inflates a balloon.

Sleep apnea machines are available only through a physician's description, and must have Food and Drug Administration (FDA) approval. The patient's physician determines, the amount of pressurized air delivered, based on the type and the severity of the patient's sleep apnea.

Several types of sleep apnea machines are available. The most common of sleep apnea machines is CPAP, or continuous positive airway pressure. A CPAP is usually about the size of a shoebox, sometimes smaller. The machine connects to the facemask via a flexible tube and works by pushing air through the tube at a high enough pressure to prevent episodes of sleep apnea.

Another type of sleep apnea machines is VPAP, or variable positive airway pressure. Also known as bi-level or BiPAP, this machine uses an electronic circuit to monitor the patient's breathing, to provide two different pressures. A higher pressure is used for inhalation, while a lower one flows for exhalation. VPAP or BiPAP is more expensive than CPAP and is sometimes used for patients who have other respiratory problems, and/or who have difficulty breathing out against pressure.

A third option is APAP, or automatic positive airway pressure. Recently approved by the FDA, this sleep apnea machine incorporates pressure sensors and a computer, which continuously monitors the patient's breathing. APAP can then automatically adjust the pressure as the patients breathing patterns shift. Of the types listed, APAP is the most sophisticated, and may be the most expensive.

Features available on sleep apnea machines include ramps, which allow the patient to begin the night's sleep at a lower pressure and ?ramp? it up as sleep deepens. Sleep apnea machines also come with a heated humidifier. Warm, moist air, along with preventing sleep apnea events, can also ease breathing and the side effects of dry mouth and sore throat upon waking. Some sleep apnea machines have the capability to monitor how often the patient uses the CPAP. Others can also record if the patient experienced any sleep apnea events while using the sleep apnea machine. The patient's physician can download this data to verify the effectiveness of treatment.

Adding a compliance motor to sleep apnea machines provides objective verification that the patient is obtaining sufficient amounts of restful sleep. For sleep apnea machines with this feature, the patient may have to take the machine into the sleep center to download data, or may send the data via a telephone modem, supplied with the machine, that does not require Internet access.